Severe mental illness may be treated psychoanalytically, pharmacologically, or directly, by stimulation of the brain. The two most popular types of direct stimulation are electric stimulation and magnetic stimulation. In either case, the stimulation may be relatively mild or of a sufficient intensity to cause a seizure. As is well known to those of skill in the art, a seizure may be particularly efficacious in the treatment of some mental illnesses.
For example, electroconvulsive therapy (“ECT”) is a treatment for severe mental illness in which a brief application of electric stimulus is used to produce a generalized seizure in a patient. The National Institutes of Health in conjunction with the National Institute of Mental Health convened a Consensus Development Conference on Electroconvulsive Therapy on Jun. 10-12, 1985. The consensus reached was that ECT was efficacious for depression (delusional and severe endogenous), acute manic episodes, and certain types of schizophrenia. Thus, researchers have established the effectiveness of ECT. However, ECT has been shown to be associated with cognitive deficits including memory loss. Moreover, a certain social stigma exists with respect to ECT.
Magnetic seizure therapy (“MST”) is a much newer treatment for severe mental illness, but with theoretically comparable results to ECT. Like ECT, MST causes a generalized seizure, with relief presumably occurring by the same biomedical pathways. However, in a critical difference from ECT, MST uses a brief application of a switching magnetic field to provide the stimulus which produces the generalized seizure via electromagnetic induction. This has a variety of benefits, including 1) magnetic fields penetrate tissue without dissipation of energy through conductance; 2) the brain stimulation can be more accurately and reliably dosed; and 3) stimulation can be limited to the brain structures essential for treatment response, thus reducing side-effects associated with ECT, such as memory impairment. (See Lisanby S H, Luber B, Schlaepfer T E, Sackeim H A, Safety and feasibility of magnetic seizure therapy (MST) in major depression: randomized within-subject comparison with electroconvulsive therapy. Neuropsychopharmacology. 2003 October, 28 (10):1852-65. Abstract stating “Compared to ECT, MST seizures had shorter duration, lower ictal EEG amplitude, and less postictal suppression. Patients had fewer subjective side effects and recovered orientation more quickly with MST than ECT. MST was also superior to ECT on measures of attention, retrograde amnesia, and category fluency.”)
The invention is directed to improved methods of MST, and hence methods of treatment for severe mental illness.